Once you have mastered the needed skills for doing osmosis and dealing with dialysis under high internal pressures, you are ready to construct a model of transpiration. Here is a diagram of a possible set-up:

Unlike the set-up needed to measure osmotic pressure, this one has the dialysis "bag" almost totally filled with a highly hypertonic solution of "PEG" (try a 25% solution). Just in case you are interested, polyethylene glycol is used in disposable diapers because it absorbs huge amounts of water. Since it is used on little tender bottoms, it must be safe to handle.

Immerse the "bag" in water, and soon osmosis will inflate the bag to becoming quite rigid ("turgid" is a better word).

You must find a plastic sleeve that fits loosely around the middle quarter of the sausage. Next you must find a piece of plastic, wood, or metal with the same size hole in it.

At that point, tie a string around one end (up around a knot), and hang the turgid "sausage" from a ring-stand at a height such that the sausage's bottom will dip about 1/3 way into water. Put the plastic sleeve in place and lower the sausage through the hole in the sheet of plastic, wood or metal.

Make the necessary adjustments so that about 1/4 to 1/3 of the sausage is above the top of the sleeve.

Start a small fan blowing on the exposed upper part of the sausage.

SUMMARY As the wind blows across the surface of the exposed upper end of the sausage, water osmoses out and evaporates. That water is replaced by that osmosing in at the bottom. That water which comes into the bottom dilutes the internal solution next to the cellophane membrane. This diluted solution is less dense than the solution further inside the sausage. Being less dense, it rises as a sort of laminar flow. As water evaporates from the top portion, it becomes more dense and should fall - probably as laminar flow down the inside of the sausage.

Careful adjustments will have to be made to both the amount of sausage dipped into the water, the speed of the fan and the amount of sausage exposed to the wind. Ideally, you want to match the influx of water in the "roots" to equal that which is evaporated in the "leaves."